Nardoaristolones B is a terpenoid derived from aristolane-type sesquiterpenoid. Nardoaristolones B possesses a nor-aristolone sesquiterpenoid skeleton with an unusual 3/4/5 tricyclic ring system.
Repellent substances generally cause insects to be driven away from, or to reject, otherwise insect-acceptable food sources or habitats. Most known repellents are only mildly toxic. A few of the known repellents, in fact, are not active poisons at all but rather prevent damage to plants/animals or articles of manufacture by making insect food sources or living conditions unattractive or offensive. Most current commercial insect repellents contain the synthetic chemical N,N-diethyl-m-toluamide (DEET) as their primary active ingredient. For instance, repellents sold under the major commercial brand names such as Off!®, Deep Woods Off!®, and Cutter® are all DEET based products and comprise 85% of insect repellent sales (Consumer Reports Buying Guide, 1994 Special Year-End Issue).
Article titled “Nootkatone is a repellent for Formosan subterranean termite (Coptotermes formosanus).” By BC Zhu et al. published in J Chem Ecol., 2001; 27(3); 523-31 first time reports nootkatone, a sesquiterpene ketone, isolated from vetiver oil as a strong repellent and toxicant to Formosan subterranean termites. The lowest effective concentration tested was 10 micrograms/g substrate.
Article titled “A General Approach toward Bakkanes: Short Synthesis of (±)-Bakkenolide-A (Fukinanolide)” by DS Reddy published in Org. Lett., 2004, 6 (19), pp 3345-3347 reports an efficient, general, and fully stereo controlled approach to the family of bakkanes. This route highlights a highly diastereoselective Diels-Alder/aldol sequence to furnish the common hydrindane precursor for the synthesis of bakkanes
Article titled “Ready Access to Functionally Embellished cis-Hydrindanes and cis-Decalins: Protecting Group-Free Total Syntheses of (±)-Nootkatone and (±)-Noreremophilane” by KL Handore et al. published in J. Org. Chem., 2013, 78 (16), pp 8149-8154 reports a simple and efficient synthesis of functionalized cis-hydrindanes and cis-decalins achieved using a sequential Diels-Alder/aldol approach in a highly diastereoselective manner. The article reports ready access to 13 new cis-hydrindanes/cis-decalins, a protecting group-free total synthesis of an insect repellent Nootkatone, and the first synthesis of a Noreremophilane using the shortest sequence.
As the existing repellents are developing resistance and have side effects. Hence, there is a need to identify and develop novel insect repellents to control the spread of various tropical diseases.